1. Field of the Invention
The present invention relates to a voltage detection circuit, more particularly, to a voltage detection circuit which requires lower power and is capable of precisely detecting a specific multiple of a reference voltage or a negative value of a specific multiple of a reference voltage.
2. Description of the Prior Art
Power management integrated circuit (PMIC) has been widely used in electronic products such as notebooks, mainboards, digital cameras, smart phones, tablet computers, etc. Detection circuits such as power on detector, signal ready detector, etc., are included in PMIC. In the prior art, detection circuits for precisely detecting a specific voltage occupy large layout area. Other simple detection circuits with smaller layout area are not such precise. Therefore, the applicant of the present invention has provided a power-on reset circuit in U.S. patent application Ser. No. 13/666,982, which is capable of precisely detecting a twice of a reference voltage, utilizes layout area efficiently, and has characteristics such as low quiescent current, low power consumption, etc.
Nevertheless, in practical applications, besides detecting a twice of a voltage value, a detection circuit may need to detect other multiple of a reference voltage, or a negative value of a multiple of a reference voltage. Therefore, how to design a detection circuit, which is capable of detecting any multiple of the reference voltage and also has characteristics such as good detection precision, efficient utilization of layout area, low quiescent current, low power consumption, etc., is a significant objective in the field.